Conventionally, only urea resin, melamine urea, melamine, phenol, and isocyanate type resin adhesives have been employed as the adhesive used in the manufacture of a wood fiber board or particleboard.
However, in view of global environmental problems and future depletion of fossil resources, adhesion technologies that use natural substances which are derived from non-fossil resources are drawing attention. For example, Patent Document 1 discloses a method for manufacturing a formed body that is characterized by including a step of adding a polycarboxylic acid in a solution state to plant-derived material that has been turned into small pieces, and applying heat and pressure.
Further, most present wood materials supplement lumber, which is a recyclable material, with a synthetic adhesive that is derived from fossil resources. In the future it is expected that there will be a strong push to move to natural adhesives. However, generally, wood bonding using naturally-derived substances takes a long time to cure, and in many cases requires a high addition ratio.